In a context of energy savings, new buildings are becoming more and more airtight. The good indoor air quality (IAQ) relies therefore more and more on mechanical ventilation systems with specific air flowrates to be met. However, in practice, ventilation ductworks are not always very airtight. The numerous issues induced by leaky ductwork have been well outlined in the literature and summed up in (Leprince et al., 2020). Yet the awareness is not forthcoming, and on-site workers do not always realize the consequences of ductwork leakages.
In particular, the electrical overconsumption induced to compensate for ductwork leakage is usually not really taken into account. This paper provides a practical methodology to estimate from simple on-site measurements the impact of ductwork leakage on:
- the fan electrical overconsumption to compensate for leakage
- the thermal losses due to pre-conditioned air leakage in non-conditioned spaces
- the IAQ quantified by the predicted percentage of dissatisfied.
These calculations can help to raise awareness on the duct leakage issue, to perform cost-benefit analyses, and encourage for example ductwork sealing interventions on existing leaky ductworks.
Practical application of this methodology is presented in another paper together with the impact of other non-conformities of ventilation systems (Hurel and Leprince, 2022).